It has been conservatively estimated that for both routine and special radiographic studies requiring accurate subject positioning, an average of 3.5 positions per subject have been required in past years. Present diagnostic procedures not only often call for more views, but also require that previously produced views be repeated at some later time with a higher degree of accuracy. This necessity exists particularly in taking X-ray photographs with the patient upright (i.e., the vertical Bucky arrangement) when taking X-rays of the neck, dorsal, and lumbar spine, pelvis, and chest. Often, radiologic technologists have either had to rely on their judgement to position patients for upright exams --which involves the possibility of human error--or have had to employ large and clumsy patient alignment apparatus of all sorts, which frequently needlessly complicates the patient alignment process. Clearly, there are many benefits from accurate positioning of X-ray patients, some of the more obvious ones being: less repeats of X-rays due to inaccurate positioning; less radiation exposure to the patient and staff by reducing repeats; reducing facility costs of film and processing due to repeats; increased efficient use of staff due to more upright studies being easily achieved; plus others.
Because of the importance of producing the highest quality X-ray examinations and reducing the cost and patient exposure due to possible repeats, proper patient alignment has been the subject of much inventive effort over the years.
Descriptions of typical prior art approaches may be found in a number of U.S. patents. Illustrative early teachings of patient alignment aids are found in U.S. Pat. Nos. 2,552,592 to Rush and 3,524,057 to Hammonds. In the 1951 Rush patent there is described a patient-positioning device consisting of a base platform mounted on rollers or casters, which carries an additional pair of platforms--the first adjustable longitudinally, the second rotatable like a turntable--all to transport and align a patient standing on the top platform relative to a vertical Bucky diaphragm for X-ray exposure. The 1970 Hammonds patent also teaches the use of a platform mounted for rotation and lateral translation on which a patient stands adjacent a variably pivotable vertical X-ray film holder.
More recent teachings of basically the same approach, that of an X-ray patient standing on various types of platforms which are then rotated and/or translated, are found in U.S. Pat. Nos. 4,719,646 to Saunders et al. and 3,700,894 to Counsell. The 1972 Counsell patient describes apparatus wherein a patient is aligned relative to an X-ray film cassette via a rotatable stand on the apparatus, which further includes means for slipping a guide element over the patient's head. The 1998 Saunders et al. patent discloses a cart-like machine having a rotatable platform for supporting and aligning a patient, particular adapted for the preparation of X-ray photographs of the leg bone, and hip and knee joint structures. While each of these prior art approaches acknowledges the importance of accurate and repeatable alignment of patients relative to X-ray film holders, they apparently are addressing the alignment task with ever-increasing apparatus complexity, and basic cost effectiveness has clearly been sacrificed. It is this cost-effective need that the present invention admirably meets with its elegant and straightforward graphical indicia approach.